1. Field of the Invention
The present invention concerns an aspect of the design and operation of cotton gins. More specifically, the present invention is directed toward a uni-grid and a multi-faceted cleaner incorporating the uni-grid for use in a cotton gin.
2. Description of the Prior Art
Since the cotton gin was first developed by Eli Whitney more than a century ago, the basic task of separating seeds, plant material, and other objects from the fibers of the cotton has remained a primary concern among cotton ginners. These various objects or "trash" are typically collected together with the raw cotton when it is harvested. This "trash" must be separated from the cotton fibers before the fibers can be processed into thread and, ultimately, into fabric.
Upon arrival to the cotton gin, the raw or harvested cotton is typically first received by a first stage cleaner or extractor. The extractor typically removes larger objects, such as burrs or sticks, while the cleaner removes smaller objects, such as seeds or plant material.
Generally, the cleaner includes a casing having an inlet for receiving the seed cotton and an outlet for expelling the seed cotton. The casing encloses a series of rotating spiked cylinders and fixed grids, where each particular grid is fixedly disposed beneath a particular cylinder. The conventional grid typically includes a plurality of square or circular bars individually welded across a series of intermediate heads, as illustrated in FIGS. 1&2. Bars 2 generally are dimensioned to traverse the entire depth of the casing from head 3 to head 7. Bars 2 are not only disposed alongside one another across intermediate heads 3, 4, 5, 6, 7, but also fixedly secured to each of heads 3, 4, 5, 6, 7, by a weldment. This weldment impedes the movability of the individual bars in relation to the intermediate heads.
The surface of the conventional grid, as constructed, includes slots 8, where the dimensions of slot 8 are determined by the distance between adjacent bars. To create the desired slot spacings, the ginner need only select a particular placement for bars 2 in relation to one another. For example, to remove large objects from the seed cotton, the slot spacings are increased in width by fixedly positioning the bars at an increased distance from one another. Alternatively, to remove only small objects from the seed cotton, the slot spacings are decreased in width by fixedly positioning the bars at a decreased distance from each other. Regardless of the chosen design, the bars, once welded to the intermediate heads, are securely fixed and, therefore, not easily removed and replaced.
To initially convey the seed cotton through the cleaner, a separator, located proximate to an upper portion of the casing, directs the air flow within the casing and projects the seed cotton and other objects to the cylinders. The separator directs the air flow in such a way that the air flow remains between the top portion of the cylinders and the upper portion of the casing. As such, the spacing between the cylinders and grids is considered to be an air plenum.
To clean the seed cotton, the spikes, which are disposed along the perimeter of the cylinder, receive the seed cotton from the inlet. Once received, the rotation of the cylinder causes the seed cotton to graze across the grid, thereby removing plant material, trash, and other objects from the seed cotton by capturing these objects and expelling them through the slot spacings. The remaining seed cotton is conveyed to the next cylinder in series where a similar process is repeated until the remaining seed cotton exits through the outlet.
Conventional cleaners, as illustrated in FIGS. 3-4 and disclosed in U.S. Pat. No. 5,392,495, issued to James L. Horn, typically incorporate a grid structure having large slot spacings, where the trash and seed cotton extracted through the slot spacings are reclaimed by a separate part of the cotton gin for further cleaning.
As depicted in FIG. 3, the cylinders of the conventional cleaner receive the seed cotton from the inlet of the cleaner. Through interaction with the cylinder, the grid removes the high density or heavy seed cotton, as well as any foreign objects, by permitting them to pass through the grid slot spacings. The low density or light seed cotton that remains is conveyed to the outlet of the casing. The high density seed cotton descending through the grid slots generally requires reclaiming and considerable recleaning because the heavy seed cotton typically includes more trash than even the harvested seed cotton. The reclaiming and recleaning of the heavy seed cotton requires additional equipment, such as an extractor, added to the cotton gin. These conventional cleaners also require several cleaning steps to sufficiently clean the seed cotton. Further, because the grids are fixed in the cleaner casing, the ginner cannot expeditiously change the grids, or more particularly the grid slot spacing, in response to the "trash" characteristics of the seed cotton.
The inability of conventional cleaners to maximize the operation and efficiency of its existing parts has created a specific need for an improvement in the design and operation of a cleaner for a cotton gin.